Until e-readers got popular the question of where to read came down to PC/laptop screen or printed book. Now it’s screen, book, or e-paper. The screen or book question usually saw the book win due to your eyes getting tired quickly reading from a backlit display. That problem was even worse back in the days of CRT. With e-paper it’s a different story.The question has now changed to whether you prefer holding a book and turning a page, or clicking a button to refresh the screen. The convenience of storing thousands of books and reading off a paper-like display is clearly winning, though, as Amazon has confirmed today.As of April this year, Amazon has stated that Kindle books are outselling printed books. For every 100 paper or hardbacks sold, Amazon sells 105 Kindle books. That fact has given Amazon its largest yearly growth for books in a decade. The rate at which e-books are selling is continuing to increase with some territories Amazon operates in, such as the UK, selling double the amount Kindle books compared to print books sales.Overall, Kindle sales are up 300% this year compared to last. When you consider Amazon has been selling printed books for 21 years, and e-books for a mere 4, it puts into perspective how much of a evolution/revolution this is for the book industry.Another surprising fact is which version of the Kindle is most popular. It seems adverts are not a turn off as Kindle with Special Offers has leaped to the top of the pile and outsells both the standard and DX models after only being available for just over a month.Read more at Amazon press releaseMatthew’s OpinionI’ve owned a Kindle for almost a year now and find myself turning to it more and more. To begin with I missed the feel of a book in my hand, but in the end convenience won out.The books I want to read are cheaper in digital form than paperback. The Kindle is very light and thin, even in its book-cover casing, but at the same time holds thousands of books making it the perfect device to throw in a bag. The month-long battery life also makes it ideal for holidays.If you’d asked me a year ago if I thought Kindle books would overtake print so quickly I’d have probably said no way. But I think anyone who has bought a Kindle will increasingly buy content for it due to the convenience and advantages it offers over printed books in a number of areas.